Apparatus and method for charging battery in a portable terminal with solar cell

ABSTRACT

An apparatus and method for charging in a portable terminal are provided. The apparatus includes a controller and a charging management unit. The controller controls the charging management unit, absorbs a solar light, and charges the battery. The charging management unit senses a charging temperature of a battery cell when the portable terminal charges the battery while the portable terminal is powered off.

PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) of a Koreanpatent application filed in the Korean Intellectual Property Office onApr. 22, 2010 and assigned Serial No. 10-2010-0037237, the entiredisclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and method for charging ina portable terminal. More particularly, the present invention relates toan apparatus and method for, when a portable terminal with a solar cellcharges a battery by a solar light while the portable terminal ispowered off, preventing the shortening of a battery lifetime that cantake place as a charging temperature of a battery cell increases.

2. Description of the Related Art

In recent years, the use of portable terminals is increasing due to theconvenience they provide. Accordingly, service providers (i.e., systemmanufacturers) are competitively developing portable terminals havingmore convenient functions to increase their user base.

For example, portable terminals are providing functions of a phone book,a game, a scheduler, a Short Message Service (SMS), a Multimedia MessageService (MMS), a Broadcast Message Service (BMS), an Internet service,an Electronic mail (e) mail service, a wake-up call, a Motion PictureExpert Group (MPEG)-1 or MPEG-2 Audio Layer-3 (MP3) player, a digitalcamera, and other similar products and services.

In order to provide mobility, portable terminals make use of chargeablebatteries as a power supply. Since the chargeable battery is limited incapacity, if the use of the portable terminal increases, a batteryconsumption time is shortened. This creates an issue in that users haveto determine a State Of Charge (SOC) of the chargeable battery for along travel or outing, and have to charge the chargeable battery bysupplying an external power source to the chargeable battery.

In order to address the above issues, portable terminals having solarcells are being introduced that employ solar power to charge thebattery.

Portable terminals with solar cells can discontinue a charging functiondepending on a charging temperature of a battery cell while charging abattery using solar power. This prevents reductions in the usefullifetime and damage to the battery cell resulting from continuouscharging using solar power.

However, portable terminals can control an operation of the chargingfunction through the above function only while powered on. When theportable terminal performs a process of charging using solar power whilepowered off, the portable terminal cannot control the charging functionbecause the portable terminal cannot sense the charging temperature ofthe battery cell while the portable terminal is powered off. As aresult, when the portable terminal performs a continuous chargingprocess via solar power while powered off, the battery may be damagedand its useful life reduced.

SUMMARY OF THE INVENTION

Aspects of the present invention are to address at least the aboveproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the present invention is toprovide an apparatus and method for improving the charging performanceof a portable terminal using a solar light.

Another aspect of the present invention is to provide an apparatus andmethod for, when absorbing a solar light while powered off, allowingautomatic entry into a power on state in a portable terminal using thesolar light.

A further aspect of the present invention is to provide an apparatus andmethod for, while absorbing a solar light while powered off, generatinga signal for allowing entry into a power on state in a portable terminalusing the solar light.

The above aspects are achieved by providing an apparatus and method forbattery charging in a portable terminal with a solar cell.

In accordance with an aspect of the present invention, an apparatus forcharging a battery in a portable terminal with a solar cell is provided.The apparatus includes a controller and a charging management unit. Thecontroller controls the charging management unit, absorbs a solar light,and charges the battery. The charging management unit senses a chargingtemperature of a battery cell when the portable terminal charges thebattery while the portable terminal is powered off.

In accordance with another aspect of the present invention, a method forcharging a battery in a portable terminal with a solar cell is provided.The method includes absorbing a solar light and charging the battery,and sensing a charging temperature of a battery cell when the portableterminal charges the battery while the portable terminal is powered off.

In accordance with another aspect of the present invention, a chargingapparatus using a solar cell is provided. The apparatus includes a solarcell panel for absorbing a solar light for charging a battery of aportable terminal and for providing an output power source to thebattery, a battery state determiner for measuring a charging voltage ofthe battery charged based on the solar light absorbed through the solarcell panel, a signal generator for generating a booting signal forbooting the portable terminal, and an operation determiner fordetermining a terminal operation state at a time when the solar cellpanel operates.

In accordance with another aspect of the present invention, a portableterminal is provided. The portable terminal includes a battery forsupplying power to the portable terminal, and a charging apparatusincluding a solar cell panel for generating power based on solar lightincident on the solar cell panel, a battery state determiner formeasuring a charging voltage of the power supplied to charge the batteryby the solar cell panel, a signal generator to generate a booting signalto boot the portable terminal when the portable terminal is powered off,and an operation determiner for determining whether to control thesignal generator to generate the booting signal.

Other aspects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a block diagram illustrating a construction of a portableterminal performing a battery charging process according to an exemplaryembodiment of the present invention;

FIG. 2 is a diagram illustrating a battery charging process of acharging management unit according to an exemplary embodiment of thepresent invention;

FIG. 3 is a flowchart illustrating a process of automatically poweringon while absorbing a solar light while powered off in a portableterminal according to an exemplary embodiment of the present invention;and

FIG. 4 is a diagram illustrating a battery charging process of aportable terminal according to an exemplary embodiment of the presentinvention.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of exemplaryembodiments of the invention as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding, but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the embodiments described hereincan be made without departing from the scope and spirit of theinvention. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but are merely used by theinventor to enable a clear and consistent understanding of theinvention. Accordingly, it should be apparent to those skilled in theart that the following description of exemplary embodiments of thepresent invention is provided for illustration purposes only and not forthe purpose of limiting the invention as defined by the appended claimsand their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

By the term “substantially” it is meant that the recited characteristic,parameter, or value need not be achieved exactly, but that deviations orvariations, including for example, tolerances, measurement error,measurement accuracy limitations and other factors known to those ofskill in the art, may occur in amounts that do not preclude the effectthe characteristic was intended to provide.

Exemplary embodiments of the present invention provide an apparatus andmethod for controlling to allow automatic entry into a power on stateand sense a charging temperature of a battery cell in case of absorbinga solar light in a power off state in a portable terminal using thesolar light according to the present invention and, due to this,improving the charging performance of the portable terminal.

FIGS. 1 through 4, described below, and the various exemplaryembodiments of the present invention provided are by way of illustrationonly and should not be construed in any way that would limit the scopeof the present invention. Those skilled in the art will understand thatthe principles of the present disclosure may be implemented in anysuitably arranged communications system. The terms used to describevarious exemplary embodiments of the present invention are providedmerely to aid the understanding of the description, and their use anddefinitions in no way limit the scope of the invention. Terms first,second, and the like are used to differentiate between objects havingthe same terminology and are in no way intended to represent achronological order, unless where explicitly state otherwise. A set isdefined as a non-empty set including at least one element.

FIG. 1 is a block diagram illustrating a construction of a portableterminal performing a battery charging process according to an exemplaryembodiment of the present invention.

Referring to FIG. 1, the portable terminal includes a controller 100, acharging management unit 102, a memory unit 112, an input unit 114, adisplay unit 116, and a communication unit 118. The charging managementunit 102 includes a solar cell panel 104, a battery state determiner106, a signal generator 108, and an operation determiner 110. Theportable terminal may include additional units that are not illustratedhere merely for sake of clarity. Similarly, the functionality of two ormore of the above units may be integrated into a single component.

The controller 100 controls general operations of the portable terminal.For example, the controller 100 performs processing and control forvoice call and data communication. In addition to these generalfunctions, the controller 100 performs a booting process for controllinga charging function making use of solar light. In order to address thereduction in battery lifetime due to the inability to measure a chargingtemperature of a battery cell when performing a charging process whilethe portable terminal is powered off, when the controller 100 receives abooting signal from the charging management unit 102, the controller 100performs a booting process and powers on the portable terminal 100.

When the solar cell panel 104 absorbs the solar light and provides anoutput power source, the charging management unit 102 determines anoperation state of the portable terminal. If the charging managementunit 102 determines that the portable terminal is powered off, thecharging management unit 102 powers on and boots the portable terminal.

The charging management unit 102 continuously determines a chargingvoltage of a battery of the portable terminal while the portableterminal charges the battery in the power off state. When the chargingvoltage is greater than or equal to a threshold, the charging managementunit 102 boots the portable terminal.

The solar cell panel 104 of the charging management unit 102 absorbs thesolar light for charging the battery of the portable terminal, andprovides an output power source to the battery.

The battery state determiner 106 of the charging management unit 102measures a charging voltage of a battery charged using a solar lightunder the control of the charging management unit 102. In order todetermine when to boot the portable terminal, the battery statedeterminer 106 measures the charging voltage of the battery. The batterystate determiner 106 can determine if circumstances indicate that theuseful lifetime of the battery may be reduced (e.g., the chargingtemperature of a battery cell is increasing, and the like) in order toboot the portable terminal.

The signal generator 108 of the charging management unit 102 generates asignal for booting the portable terminal being in the power off state.The signal generator 108 generates a signal for powering on the portableterminal and provides the signal to the controller 100, when thecharging management unit 102 determines that the portable terminal ispowered off and is performing a charging process using a solar light.

The operation determiner 110 determines an operation state of theportable terminal. The operation determiner 110 determines if theportable terminal is powered on or powered of, when the solar cell panel104 operates.

The memory unit 112 may include a Read Only Memory (ROM), a RandomAccess Memory (RAM), a flash ROM, or other similar storage devices. TheROM stores a microcode of a program for processing and controlling thecontroller 100 and the charging management unit 102 and a variety ofkinds of reference data.

The RAM, a working memory of the controller 100, stores temporary datagenerated in execution of a variety of kinds of programs. The flash ROMstores several types of updateable depository data such as a phone book,an outgoing message, an incoming message, and the like.

The input unit 114 may include numeral key buttons ‘0’ to ‘9’, a menubutton, a cancel button, an OK button, a talk button, an end button, anInternet button, navigation key buttons, a plurality of function keyssuch as a character input key and other similar input keys and buttons.The input unit 114 provides key input data corresponding to a keypressed by a user to the controller 100.

The display unit 116 displays state information generated during theoperation of the portable terminal, limited number of characters, alarge amount of moving pictures and still pictures, and the like. Thedisplay unit 116 can be a color Liquid Crystal Display (LCD), an ActiveMode Organic Light Emitting Diode (AMOLED) display, and other similardisplay apparatuses. When the display unit 116 includes a touch inputdevice and is applied to a portable terminal of a touch input scheme,the display unit 116 can be used as an input device of the portableterminal.

The communication unit 118 transmits/receives and processes a wirelesssignal of data input/output through an antenna (not illustrated). Forexample, in a transmission mode, the communication unit 118 processesoriginal data through channel coding and spreading, converts theoriginal data into a Radio Frequency (RF) signal, and transmits the RFsignal. In a reception mode, the communication unit 118 converts areceived RF signal into a baseband signal, processes the baseband signalthrough de-spreading and channel decoding, and restores the signal tooriginal data.

A role of the charging management unit 102 can be implemented by thecontroller 100 of the portable terminal. However, these are separatelyconstructed and shown herein as an exemplary construction fordescription convenience, and not to limit the scope of the presentinvention. It would be understood by those skilled in the art thatvarious modifications of construction can be made within the scope ofthe present invention. For example, construction can also be such thatall of the disclosed functions are processed in the controller 100.

FIG. 2 is a diagram illustrating a battery charging process of acharging management unit according to an exemplary embodiment of thepresent invention.

Referring to FIG. 2, when the charging management unit 102 charges abattery using a solar light while the portable terminal is powered off,the charging management unit 102 can discontinue a charging functiondepending on a charging temperature of a battery cell.

The charging management unit 102 absorbs, by a solar cell panel 104, asolar light and provides the solar light as an output power source 103of a battery 105, thereby attempting battery charging.

The operation determiner 110 of the charging management unit 102determines an operation state of the portable terminal. For example, theoperation determiner 110 determines whether the portable terminal ispowered off in order to determine when to perform a booting process forcontrolling a charging function making use of a solar light (i.e., acharging function discontinued depending on a charging temperature of abattery cell).

When the operation determiner 110 determines that the portable terminalis in a power on state, the controller 100 can discontinue the chargingfunction depending on the charging temperature of the battery cell.

On the other hand, when the operation determiner 110 determines that theportable terminal is powered off, the controller 100 is unable todetermine the charging temperature of the battery cell.

Accordingly, the battery state determiner 110 processes a signalgenerator 108 to generate a booting signal when the battery statedeterminer 110 determines that a charging voltage of a battery 105 isgreater than or equal to a threshold or determines that the solar cellpanel 104 operates while the portable terminal is powered off.

If the signal generator 106 receives a request for generating a bootingsignal from the battery state determiner 106 as above, the signalgenerator 108 provides the booting signal to the controller 100 andchanges an operation mode from the power off state to the power onstate.

FIG. 3 is a flowchart illustrating a process allowing automatic entryinto a power on state when absorbing a solar light while a portableterminal is powered off according to an exemplary embodiment of thepresent invention.

Referring to FIG. 3, the portable terminal and determines whether asolar cell panel operates in step 301. The portable terminal determinesif the solar cell panel is exposed to a solar light to absorb the solarlight and charge a solar cell.

If it is determined that the solar cell panel does not operate in step301, the portable terminal proceeds to step 315 and performs acorresponding function (e.g., a wait mode).

On the other hand, if it is determined that the solar cell paneloperates in step 301, the portable terminal proceeds to step 303 andprocesses to generate an output power for battery charging through thesolar cell panel that absorbs the solar light. In this fashion, theportable terminal enables the battery charging using the solar lightwithout external power source supply.

The portable terminal proceeds to step 305 and determines an operationstate of the portable terminal. The portable terminal determines whetherthe portable terminal is powered on or powered off. This is to determinewhen to boot the portable terminal, because the portable terminal cannotcontrol a charging function making use of a solar light, e.g., cannotdiscontinue the charging function depending on a charging temperature ofa battery cell while the portable terminal is powered off.

The portable terminal proceeds to step 307 and determines the result ofstep 305. If it is determined that the portable terminal is powered offin step 307, the portable terminal determines that it is time to performa booting process for controlling the charging function making use ofthe solar light in the portable terminal.

After determining that it is time to perform the booting process asabove, the portable terminal proceeds to step 309 and generates a signalfor terminal operation. The portable terminal proceeds to step 311 andboots the portable terminal. The portable terminal processes a signalgenerator of a charging management unit to generate a signal forterminal operation and, after determining that the signal generatorgenerates the signal for terminal operation, the charging managementunit boots the portable terminal.

The portable terminal proceeds to step 313 and charges a battery. Theportable terminal proceeds to step 317 and determines a state of thebattery. The portable terminal determines the state of the battery inorder to discontinue the charging function depending on the chargingtemperature of the battery cell.

If it is determined that the portable terminal is in the power on statein step 307, the portable terminal proceeds to step 317 and determinesthe state of the battery.

The portable terminal proceeds to step 319 and determines whethercircumstances indicate that the useful lifetime of the battery is beingreduced. Such circumstances may occur, for example, when the chargingtemperature of the battery cell is greater than or equal to a thresholdor more. This may indicate that the charging function is to beautomatically discontinued.

If it is determined that the situation of shortening the lifetime of thebattery does not take place in step 319, the portable terminal againperforms the procedure of step 317.

On the other hand, if it is determined that the useful lifetime of thebattery is being reduced in step 319, the portable terminal proceeds tostep 321 and terminates the operation of the solar cell panel to preventthis reduction.

FIG. 4 is a diagram illustrating a battery charging process of aportable terminal according to an exemplary embodiment of the presentinvention.

Referring to FIG. 4, the portable terminal can charge a solar cellthrough a solar cell panel. The portable terminal can be located in anarea 403 exposed to a solar light or an area 401 not exposed to thesolar light.

As the solar cell panel absorbs a solar light and charges the solarcell, the portable terminal can charge the solar cell when the portableterminal is located (410) in the exposure area 403, and the portableterminal cannot charge the solar cell when the portable terminal islocated (412) in the non-exposure area 401.

For example, when the portable terminal located (410) in the exposurearea 403 charges the solar cell while powered on, the portable terminalperiodically determines a state of a battery (i.e., a chargingtemperature of a battery cell) and determines whether circumstancesindicate that the useful lifetime of the battery is being reduced. Ifthese circumstances are occurring, the portable terminal discontinues anoperation of the solar cell panel, discontinuing a process of chargingthe solar cell.

On the other hand, when the portable terminal located (410) in theexposure area 403 moves (412) to the non-exposure area 401, the portableterminal cannot perform the process of charging the solar cell by asolar light. If the portable terminal remains in the non-exposure area401, battery consumption occurs and a situation where the portableterminal powers off takes place (414).

In addition, if the portable terminal moves to the exposure area 403after power is off as heavy battery consumption takes place although theportable terminal is located (410) in the exposure area 403 or power isoff as the portable terminal remains in the non-exposure area 401 asdescribed above, the portable terminal charges (416) the solar cell in apower off state.

When the portable terminal charges (416) the solar cell in the power offstate as above, the portable terminal cannot sense the chargingtemperature of the battery cell, so the portable terminal is not able tocontrol a battery charging function. As a result, if the portableterminal performs a continuous charging procedure while powered off(418), the useful lifetime of the battery may be reduced and damage tothe battery may occur due to the solar light.

In order to address the above issue, the portable terminal determines(420) when the solar cell is charged while the portable terminal ispowered off or a time when a battery voltage is greater than or equal toa threshold in course of charging the solar cell while the portableterminal is powered off, through a separate charging management unitsuch as a MIcroCOMputer (MICOM), and generates a signal for booting theportable terminal at the determined time. If the signal is generated,the portable terminal powers on. Accordingly, when the chargingtemperature of the battery cell is greater than or equal to a threshold,the portable terminal can discontinue (422) a battery charging processusing a solar light. The charging management unit can be composed of aseparate device such as a MICOM, so the charging management unit canperform, though the portable terminal powers off, a procedure forbooting the portable terminal through low power charged by the solarlight.

In this fashion, the portable terminal can address the battery lifetimeshortening problem that occurs as the solar cell is continuously chargedwhile the portable terminal is powered off due to battery consumption.

As described above, exemplary embodiments of the present invention,which relate to an apparatus and method for improving chargingperformance in a portable terminal making use of a solar light, in acase where a solar cell panel operates in a power off state, cangenerate a signal for booting the portable terminal, thereby allowingentry into a power on state and then measuring a charging temperature ofa battery cell.

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. An apparatus for charging a battery in a portableterminal with a solar cell, the apparatus comprising: a controller forcontrolling a charging management unit, for absorbing a solar light, andfor charging the battery; and the charging management unit for sensing acharging temperature of a battery cell when the battery is being chargedwhile the portable terminal is powered off.
 2. The apparatus of claim 1,wherein the charging management unit boots the portable terminal andsenses the charging temperature of the battery cell.
 3. The apparatus ofclaim 1, wherein, when the charging management unit determines that asolar cell panel is operating while the portable terminal is poweredoff, the charging management unit generates a booting signal for bootingthe portable terminal, and boots the portable terminal according to thegeneration of the booting signal.
 4. The apparatus of claim 1, whereinthe charging management unit determines the charging temperature of thebattery cell of the portable terminal after determining whether a solarcell panel is operating while the portable terminal is powered off, andgenerates a booting signal for booting the portable terminal when thecharging temperature of the battery cell is greater than or equal to athreshold.
 5. The apparatus of claim 1, wherein the charging managementunit is constructed using a MIcro COMputer (MICOM) that can be driven atlow power while the portable terminal is powered off.
 6. A method forcharging a battery in a portable terminal with a solar cell, the methodcomprising: absorbing a solar light and charging the battery; andsensing a charging temperature of a battery cell when the battery isbeing charged while the portable terminal is powered off.
 7. The methodof claim 6, wherein the sensing of the charging temperature of thebattery cell when the battery is being charged while the portableterminal is powered off comprises booting the portable terminal.
 8. Themethod of claim 6, wherein the sensing of the charging temperature ofthe battery cell when the battery is being charged while the portableterminal is powered off comprises: when the portable terminal is poweredoff and a solar cell panel is operating, generating a booting signal forbooting the portable terminal; and booting the portable terminalaccording to the generation of the booting signal.
 9. The method ofclaim 8, wherein the generating of the booting signal comprises: afterthe portable terminal determines that the solar cell panel is operatingwhile the portable terminal is powered off, determining the chargingtemperature of the battery cell of the portable terminal; and if thecharging temperature of the battery cell is greater than or equal to athreshold or more, generating the booting signal.
 10. The method ofclaim 8, wherein the generating of the booting signal is performed usinga MIcro COMputer (MICOM) that can be driven at low power while theportable terminal is powered off.
 11. A charging apparatus using a solarcell, the apparatus comprising: a solar cell panel for absorbing a solarlight for charging a battery of a portable terminal, and for providingan output power source to the battery; a battery state determiner formeasuring a charging voltage of the battery charged based on the solarlight absorbed through the solar cell panel; a signal generator forgenerating a booting signal for booting the portable terminal; and anoperation determiner for determining a terminal operation state at atime when the solar cell panel operates.
 12. The apparatus of claim 11,wherein, when the solar cell panel is determined to be operating whilethe portable terminal is powered off, the signal generator generates thebooting signal.
 13. The apparatus of claim 11, wherein, when the batterystate determiner determines that a charging temperature of a batterycell is greater than or equal to a threshold, the signal generatorgenerates the booting signal.
 14. The apparatus of claim 11, whereinoperations of the battery state determiner, the signal generator, andthe operation determiner are implemented using a Micro Computer (MICOM)that can be driven at low power while the portable terminal is poweredoff.
 15. The apparatus of claim 11, further comprising a controller for,after the portable terminal is booted, terminating an operation of thesolar cell panel if a charging temperature of a battery cell is greaterthan or equal to a threshold.
 16. A portable terminal comprising: abattery for supplying power to the portable terminal; and a chargingapparatus including: a solar cell panel for generating power based onsolar light incident on the solar cell panel; a battery state determinerfor measuring a charging voltage of the power supplied to charge thebattery by the solar cell panel; a signal generator to generate abooting signal to boot the portable terminal when the portable terminalis powered off; and an operation determiner for determining whether tocontrol the signal generator to generate the booting signal.
 17. Theportable terminal of claim 16, wherein the operation determiner controlsthe signal generator to generate the booting signal when the operationdeterminer determines that the solar cell panel is generating powerwhile the portable terminal is powered off.
 18. The portable terminal ofclaim 16, wherein, when the battery state determiner determines that thecharging voltage is greater than or equal to a predetermined threshold,the battery state determiner controls the signal generator to generatethe booting signal.
 19. The portable terminal of claim 16, wherein thecharging apparatus is detachably coupled to the portable terminal.